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26 PS Series Asynchronous Replication Best Practices and Sizing Guide | BP1012
6.9 Server I/O effects
Asynchronous replication is a background process, and as such is designed to have little impact on the
performance of servers (hosts) connected to the SAN. On the other hand, that means that server I/O can
affect the performance of replication. If there is a heavier workload from the attached hosts, the arrays may
devote fewer resources to replication, which could cause replication times to be longer than when there is a
lighter workload from the attached hosts.
Server I/O is another factor that you should take into account when considering recovery time objective (RTO)
or recovery point objective (RPO) times. By using SAN Headquarters to monitor the I/O load and replication
times, this can ensure that there is enough headroom built into the SAN to accommodate a difference in
workload from day to day or during different parts of the day if multiple replicas are created.